A major contraceptive breakthrough could radically change how we manage birth control as soon as five years from now.
British scientists have discovered a fast-acting peptide that temporarily immobilises sperm and raises the possibility of a male pill, implant - or even a nasal spray - being available by 2021.
"The results are startling - and almost instant," lead researcher, Wolverhampton University's Professor John Howl, told the The Mail On Sunday. "When you take healthy sperm and add our compound, within a few minutes the sperm basically cannot move."
The British team worked with Portuguese researchers to recreate the effects of low-motility sperm and came up with a compound called a cell-penetrating peptide, which pauses the movement of sperm and therefore prevents the fertilisation of eggs. They said the sperm-blocking effects wear off within days.
While preventing pregnancy is generally accepted as a joint responsibility, the lack of male contraceptive options means it is a burden that often falls on women, with a third of British adult females currently taking the pill. As well as redressing this imbalance, a male contraceptive pill would provide more choice to couples in which the woman can't take the pill for medical reasons.
Women in Britain have had access to oral birth control since 1961, though officially it was only available to married women until 1974. Its accessibility heralded a sexual revolution and a transfer of control over reproductive rights from men to women at a time when the move to dismantle gender inequality was making huge strides. Abortion was legalised in 1967, followed in 1970 by the inception of the Equal Pay Act and in 1975 by the Sex Discrimination Act.
While gender equality has advanced light years since the pill was made available, male contraception has remained confined to condoms and vasectomies - this breakthrough could even out the management of family planning between men and women.